A Tropical Depression or Tropical Storm is Expected in the Gulf of Mexico, Will Likely Soak Parts of

A tropical depression or tropical storm will likely form in the Gulf of Mexico, possibly as soon as later Sunday, bringing a threat of heavy rain to parts of Florida and the Southeast coast Monday and Tuesday.

Clusters of thunderstorms continue to flare up in the western Caribbean Sea, but, as yet, have not consolidated in any one location to form a tropical cyclone.

This is partly due to persistent west winds in the upper levels of the atmosphere flowing atop near-surface easterly winds, providing enough wind shear to prevent thunderstorms from consolidating and persisting, for now.

As of 8 a.m. Sunday, the National Hurricane Center has given this system, Invest 93L, a 90 percent chance of developing into a tropical depression or tropical storm withing 48 hours.

An area of low pressure is located near the northeastern portion of the Yucatan Peninsula, as of Sunday morning, and surface pressures are falling in the area. Winds to near tropical storm force have been observed in the northwestern Caribbean Sea. Conditions are expected to be favorable for further development Sunday.

Even without additional development, areas of locally heavy rain are likley in western Cuba, possibly as far west as Cancun and Cozumel, Mexico.

With upper-level high pressure centered to the east from the Bahamas to the central Caribbean Sea and broad low pressure aloft centered over South Texas, this area of disturbed weather will be steered into the Gulf of Mexico early this week.

It remains too soon to determine...

  • How much this disturbance will strengthen. At a minimum, it is expected to become a tropical depression (maximum winds less than 39 mph), but could strengthen to a tropical storm.

  • Exactly where it will track.

The National Hurricane Center canceled a Saturday afternoon Air Force Reserve Hurricane Hunter mission due to the lack of organization of the disturbance in the western Caribbean Sea. However, another mission has been scheduled for Sunday afternoon.

For now, the majority of forecast guidance suggests the upper-level features described earlier will curve the disturbance, in whatever form it takes, toward the Florida Peninsula sometime in the late-Monday or early Tuesday timeframe, then somewhere near or off the coast of the Carolinas by later Tuesday.

It will not have much time to strengthen appreciably, and at least some wind shear will remain it place as it tracks toward the Gulf Coast.

If it becomes a tropical storm, it would be named "Colin", the season's third named storm.

Regardless of whether it develops, the upper-level wind pattern discussed earlier is likely to set up a plume of deep, tropical moisture over parts of the Sunshine State and Southeast coast as the system tracks through.

Thus, areas of heavy rain and flash flooding appear likely, even ahead of the arrival/landfall of the surface low-pressure center to the east, northeast and southeast of the track of the system.

The rainfall outlook is uncertain beyond Florida, as the system may intercept a cold front arriving from the Appalachians (a common heavy-rain scenario), but also be accelerating quickly out to sea (minimizing the duration of any heavy precipitation).

If the disturbance does develop into a tropical storm, some coastal flooding can be expected along Florida's vulnerable Gulf Coast, mainly to the northeast, east and southeast of the center.

Gusty winds and even a few tornadoes are also possible as the system passes through late Monday into early Tuesday.

If you have vacation plans in Florida or along the Southeast coast, we don't yet suggest canceling those plans. But do check back with us at weather.com for the latest on this system.

However, be aware there may be a period of time Monday and Tuesday where rainfall in parts of Florida won't simply be the passing afternoon thunderstorm with a brief heavy downpour, but rather a more prolonged bout of rain, possibly heavy at times.

Incidentally, this part of the Gulf of Mexico and western Caribbean is a common area for June tropical cyclone development.

( Source )